Design and Optimization of a Multidirectional Anti-Misalignment Magnetic Coupler for Oil Drilling Rotary Steerable Systems

To address power fluctuations caused by polar angle misalignment in rotary wireless power transfer (RWPT) for oil drilling rotary steerable systems (RSS), a novel three layers orthogonal magnetic coupler has been proposed. The proposed magnetic coupler uses a three-layer DD coil structure, with mutually orthogonal magnetic fields, which was utilized to generate mutual inductance to remain stable during rotation, with minimal variations under axial, radial, and polar angle misalignments. A design optimization method integrating Finite element analysis (FEA) and sequential mixed-integer nonlinear programming (SMINLP) is proposed, determining optimal mutual inductance and finding matching structural parameters, which save time of simulation and experiment. Compared to existing magnetic couplers, the proposed magnetic coupler exhibits tolerance against 360° full-space misalignment. At last, the prototype validates the multi-directional anti-misalignment capability of the proposed magnetic coupler.